An annotation tool for coreference

Coref Annotator
Annotation Concepts
Import and Export

Coref Annotator

This is yet another annotation tool, this time for coreference. It’s built on top of Apache’s UIMA, and works with long documents and long coreference chains.



CorefAnnotator is an annotation tool for coreference, i.e., to mark whenever two or more words in a text refer to the same thing in the real world. We will refer to the words in a text as mentions and to the things in the real world as entities. Entities don’t have to be touchable or concrete.

CorefAnnotator displays two views: The text on the left, and a tree on the right. Mentions in the text can be selected with a point device (e.g., mouse). To create a new entity in the tree on the right, either drag the selected mention onto the root node of the tree, or click “new” in the tool bar. Newly created entities then get a color assigned, and all their mentions in the text are underlined with the color. Selecting a mention in the tree also selects the mention in the text (and scrolls to an appropriate position if necessary). Clicking on a mention in the text view shows a context menu with all mentions that cover a certain text span. From there, one can reveal the mention in the tree or directly delete id.

In addition to a color, each entity has an assigned key code. This single letter shortcut can be used to quickly assign mentions to entities (without dragging). Both colors and key codes can be changed at any time, as can the name of the entity that is displayed in the tree.